The 'I' and the 'Me' in self-referential awareness: a neurocognitive hypothesis.

The nature of the 'self' and self-referential awareness has been one of the most debated issues in philosophy, psychology and cognitive neuroscience. Understanding the neurocognitive bases of self-related representation and processing is also crucial to research on the neural correlates of consciousness. The distinction between an 'I', corresponding to a subjective sense of the self as a thinker and causal agent, and a 'Me', as the objective sense of the self with the unique and identifiable features constituting one's self-image or self-concept, suggested by William James, has been re-elaborated by authors from different theoretical perspectives. In this article, empirical studies and theories about the 'I' and the 'Me' in cognition and self-related awareness are reviewed, including the relationships between self and perception, self and memory, the development of the self, self-referential stimulus processing, as well as related neuroimaging studies. Subsequently, the relations between self and different aspects of consciousness are considered. On the basis of the reviewed literature and with reference to Block's distinction between phenomenal and access consciousness, a neurocognitive hypothesis is formulated about 'I'-related and 'Me'-related self-referential awareness. This hypothesis is extended to metacognitive awareness and a form of non-transitive consciousness, characteristic of meditation experiences and studies, with particular reference to the notion of mindfulness and other Buddhist constructs.